Alexandre joseph marin



UNITED STATES PATENT OFFICE.

ALEXANDRE JOSEPH MARIN, OF PARIS, FRANCE.

rREPARA'rI'oN or AN oxYenN-oAaaxrNe SALT SUITABLE Eon THE MANUFACTURE or EXPLOSIVES, AND rRoo ss FOR MAKING THESE EXPLOSIVES.

No Drawing.

T 0 all whom it may concern:

Be it known that I, ALEXANDRE J OSEPH MARIN, a subject of the King of the Belgians, residing at 10 Rue dOfi'emont, Paris, France, have invented certain new and useful Improvements in Preparation of an Oxygen-Carrying Salt Suitable for the Manufacture of Explosives, and Processes for Making These Explosives, of which the following is a specification.

The mixture in equimolecular proportion of the oxidizing salts, sodium nitrate and ammonium perchlorate, from the point of view of the manufacture of explosives requires special attention by reason of properties which may be summarized as follows (1) They contain 55.3% oxygen of which 39.5% is available for the combustion of added materials, such as hydrocarbons, nitrated or not, &c. (2) Even with hydrocarbons strongly nitrated such as trinitrotoluene, explosives are obtained which are combustible with difficulty similar to those explosives based on ammonium nitrate. (3) In spite of their slight sensibility to fire on shock the explosives thus formed may be easily fired by the usual detonators used for industrial purposes. (4:) These explosives may be compressed without deteriorating their detonating properties, their power is practically the same as that of explosives formed only of ammonium perchlorate and hydrocarbons, nitrated or not, and all have a low cost price.

Up to the present these explosives have been prepared by mixing the three ingredients, (the solids being reduced to powder, and the combustibles, if liquid, being used as such,) by means of the usual apparatus employed in the art. But it is to be noted that the manufacture of ammonium perchlorate is effected commercially by breaking down sodium perchlorate and by a double decomposition with an ammonium salt, generally the chlorid or the sulfate. (In these conditions by-products such as sodium chlorid or sodium sulfate are obtained which must be carefully eliminated because their presence destroys the qualities of the explosive.) I have found that if in place of the ammonium chlorid or ammonium sulfate, use is made of ammonium nitrate to effect the double decomposition precisely th same final result is obtained as regards Specification of Letters Patent.

Patented. Oct. 28, 1919.

Application filed June 11, 1918. Serial No. 239,479.

the ammonium perchlorate and sodium nitrate in equimolecular quantity. I have also found that it is not necessary to separate the two salts which separation would present difliculties as-a result of the tendency for the ammonium perchlorate and sodium nitrate to form double salts of which the solubility when cold is much greater than that of the ammonium perchlorate and less than that of the sodium ni. trate. In carrying out this part of the invention a solution of concentrated sodium perchlorate has an equivalent quantity of ammonium nitrate added thereto. The mixture thickens rapidly owing to the formation of the double salt which is produced in the form of a white powder composed of microscopic crystals. Finally, after desiccation a mixture is obtained of ammonium perchlorate, sodium nitrate and double salts roughly in the form l Tal TI-I,GlO= NO* as hereinbefore referred to.

Too small a quantity of ammonium nitrate leaves free in the mixture a certain quantity of sodium perchlorate the presence of which would be detrimental to the qualities of the explosive owing to the extreme hygroscopic qualities of this salt. An excess of ammonium nitrate is preferable.

By following the direct preparation of the oxidizing saline mixture as it may be called, it is possible to use another special mode of manufacturing explosives derived therefrom as shown by the following examples of carrying out the invention as regards this manufacture.

1st emampZe.-An intimate mixture is made of 72 parts by weight of ammonium nitrate with 127 parts by weight of trinitrobenzin and is stirred with a very concentrated solution of sodium perchlorate, in which solid salt may be present and which contains altogether 110 parts of dry perchlorate. After stirring the mixture until it is almost solid, it is treated in a disintegrator and after it has been dried and contains no more than 2 to 4% of moisture it is molded into cartridges and then finally dried.

The concentrated solution may contain about 50% of Water without inconvenience, but it is preferable to use as small an amount of water as possible. The preferable temperature varies between 15 and 50 C.

In this preparation trinitro-benzin may be replaced with equivalent quantities of other hydrocarbons, such as dinitrobenzin, the solid diand-trinitro-toluenes, and the mono, di-and-tri-nitronaphthalene.

2nd ewampZe.An intimate mixture is made with 64 parts by weight of ammonium nitrate and 123 parts of ammonium picrate; this mixture is triturated with a concentrated solution of sodium perchlorate containing 98 parts by weight of anhydrous sodium perchlorate and the process is completed as in the first example.

In this last mixture ammonium picrate can be replaced by an equivalent quantity of ammonium trinitrocresylate.

If combustible or explosive liquids be used the process must be finished in another way The product is dried during trituration in a kind of disintegrating apparatus and afterward put into cartridges.

Intermediary formation of double salts duringthe double decomposition between the sodium perchlorate and the ammonium nitrate plays an important part in the method of preparing explosives; it prevents the salts formed from separating by crystallization and thereby destroying the homogeneity of the mixture. It also prevents any reformation of sodium perchlorate and ammonium nitrate by reversible reaction.

Experience shows that only a mixture in equimolecular proportions of sodium perchlorate and ammonium nitrate gives solid and yet moist products which possess after desiccation an hygroscopicity less than either of the two salts employed and not greater than that of a mixture of ammonium perchlorate and sodium nitrate made in the same proportions.

I claim 1'. In a process for the manufacture of explosives the use as oxidizin r material of a mixture of ammonium perchlorate, double salts of the formula N aNI-I ClO NO and of sodium nitrate obtained directly by mixing equimolecular proportions of sodium perchlorate and ammonium nitrate in the presence of water, and desiccating and pulverizing the resulting product.

2. In a process for the manufacture of ex plosives effecting the double decomposition between sodium perchlorate and ammonium nitrate after having previously mixed the latter salt with a nitro-aromatic explosive, the sodium perchlorate being employed in a concentrated solution, and drying the resulting product.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALEXANDRE JOSEPH MARIN.

Witnesses:

CHAS. P. PRESSLY, EMILE BERTRAND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. O. 

